Work stool



FIG. 1 is a perspective view of a work stool showing our new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a right side elevational view thereof, the left side elevational view thereof being a mirror image; and

FIG. 5 is a bottom plan view thereof. 

The ornamental design for a work stool, substantially as shown and described. 